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A103758
Numbers n such that the string 100n is the decimal expansion of a prime number.
1
9, 37, 39, 61, 67, 69, 79, 91, 93, 99, 103, 109, 129, 151, 153, 169, 183, 189, 193, 207, 213, 237, 267, 271, 279, 291, 297, 313, 333, 343, 357, 361, 363, 379, 391, 393, 403, 411, 417, 447, 459, 469, 483, 493, 501, 511, 517, 519, 523, 537, 547, 549, 559, 591
OFFSET
1,1
COMMENTS
n such that n + 10^(2+A055642(n)) is prime. - Robert Israel, Feb 23 2016
LINKS
EXAMPLE
9 is in the sequence because 1009 is prime.
99 is in the sequence because 10099 is prime.
103 is in the sequence because 100103 is prime.
MAPLE
select(n -> isprime(n + 10^(3+ilog10(n))), [$1..10^3]); # Robert Israel, Feb 23 2016
MATHEMATICA
Select[Range[600], PrimeQ[FromDigits[Join[{1, 0, 0}, IntegerDigits[#]]]]&] (* Harvey P. Dale, Sep 02 2020 *)
PROG
(Magma) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [0, 0, 1])) ];
(Magma) [n: n in [1..600] | IsPrime(n+10^(2+#Intseq(n)))]; // Vincenzo Librandi, Feb 24 2016
(PARI) isok(n) = isprime(eval(concat(Str(100), Str(n)))); \\ Michel Marcus, Feb 23 2016
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Mar 28 2005
EXTENSIONS
More terms from Vincenzo Librandi, Feb 01 2011
STATUS
approved